diff --git a/lib/core/src/lib/clipboard/clipboard.directive.ts b/lib/core/src/lib/clipboard/clipboard.directive.ts
index 6d07593786..9ffb254768 100644
--- a/lib/core/src/lib/clipboard/clipboard.directive.ts
+++ b/lib/core/src/lib/clipboard/clipboard.directive.ts
@@ -42,7 +42,7 @@ export class ClipboardDirective implements OnDestroy {
     private mouseLeaveTimeout: ReturnType<typeof setTimeout>;
 
     constructor(
-        private clipboardService: ClipboardService,
+        private readonly clipboardService: ClipboardService,
         public viewContainerRef: ViewContainerRef
     ) {}